1 files changed, 64 insertions, 0 deletions
diff --git a/pre_commit/error_handler.py b/pre_commit/error_handler.py
new file mode 100644
index 0000000..b2321ae
--- /dev/null
+++ b/pre_commit/error_handler.py
@@ -0,0 +1,64 @@
+import contextlib
+import functools
+import os.path
+import sys
+import traceback
+from typing import Generator
+
+import pre_commit.constants as C
+from pre_commit import output
+from pre_commit.store import Store
+from pre_commit.util import force_bytes
+
+
+class FatalError(RuntimeError):
+    pass
+
+
+def _log_and_exit(msg: str, exc: BaseException, formatted: str) -> None:
+    error_msg = f'{msg}: {type(exc).__name__}: '.encode() + force_bytes(exc)
+    output.write_line_b(error_msg)
+    log_path = os.path.join(Store().directory, 'pre-commit.log')
+    output.write_line(f'Check the log at {log_path}')
+
+    with open(log_path, 'wb') as log:
+        _log_line = functools.partial(output.write_line, stream=log)
+        _log_line_b = functools.partial(output.write_line_b, stream=log)
+
+        _log_line('### version information')
+        _log_line()
+        _log_line('```')
+        _log_line(f'pre-commit version: {C.VERSION}')
+        _log_line('sys.version:')
+        for line in sys.version.splitlines():
+            _log_line(f'    {line}')
+        _log_line(f'sys.executable: {sys.executable}')
+        _log_line(f'os.name: {os.name}')
+        _log_line(f'sys.platform: {sys.platform}')
+        _log_line('```')
+        _log_line()
+
+        _log_line('### error information')
+        _log_line()
+        _log_line('```')
+        _log_line_b(error_msg)
+        _log_line('```')
+        _log_line()
+        _log_line('```')
+        _log_line(formatted)
+        _log_line('```')
+    raise SystemExit(1)
+
+
+@contextlib.contextmanager
+def error_handler() -> Generator[None, None, None]:
+    try:
+        yield
+    except (Exception, KeyboardInterrupt) as e:
+        if isinstance(e, FatalError):
+            msg = 'An error has occurred'
+        elif isinstance(e, KeyboardInterrupt):
+            msg = 'Interrupted (^C)'
+        else:
+            msg = 'An unexpected error has occurred'
+        _log_and_exit(msg, e, traceback.format_exc())